Modeling mid-rotation growth and mortality in boreal mixedwoods

西部北方混交林地区是一个4800万公顷的落叶针叶林混交林带，从落基山脉北部延伸到马尼托巴西南部，占地面积约为阿尔伯塔省的75%。该地区广泛的工业森林管理是最近才开始的。因此，迄今为止，支持可持续管理的监测计划一直遵循最感兴趣的立场；自25年前开始积极植树造林以来种植的幼林，以及即将采伐的70年及以上的天然林分。缺乏中年（25-70岁）混合树种林分和年轻的白云杉占主导地位（<70岁）林分的数据，阻碍了我们准确预测采伐或自然干扰后森林发展的能力。在林分发育的中期，主要树种白杨和白云杉的生长率和死亡率及其相互影响的量化程度很差。本提案中包括的研究将调查这些物种的相互作用。将利用树木年轮测量、历史上的白云杉放生试验和我们自己的目标监测地块。结果将纳入森林生长的计算机模拟模型，该模型评价这些因素的相对重要性，为森林规划提供工具，并支持干预决策（苗木选择、种植、照料和间伐），以有效管理西部北方森林。

The western boreal mixedwood forest region is a 48 million hectare band of mixed deciduous-coniferous forest extending from the northern Rocky mountains to southwestern Manitoba, covering an area about 75% the size of Alberta. Widespread industrial forest management of this region is relatively recent. As a result, the monitoring programs which support sustainable management have so far followed the stands of most interest; the young stands which were planted since active reforestation efforts began 25 years ago, and the 70-year and older natural-origin stands which will soon be harvested. A lack of data for mid-aged (25-70 year old) mixed-species stands and younger white spruce dominated (<70 year old) stands is hindering our ability to accurately predict forest development following harvesting or natural disturbance. Rates of growth and mortality of the major species, aspen and white spruce, and their effects on each other during these middle years of stand development are poorly quantified. The studies included in this proposal will investigate these species interactions. Tree-ring measurements, a historical white spruce release trial, and our own targeted monitor plots will be utilized. Results will be integrated into a computer simulation model of forest-growth which evaluates the relative importance of these factors, provides a tool for forest planning, and supports intervention decisions (nursery stock selection, planting, tending, and thinning) for effective management of the western boreal forest.